Do Busier Surgeons Have Lower Intraoperative Costs? An Analysis of Anterior Cervical Discectomy and Fusion Using Time-Driven Activity-Based Costing

STUDY DESIGN

The present study is a single-center, retrospective cohort study of patients undergoing neurosurgical anterior cervical discectomy and fusion (ACDF).

OBJECTIVE

Our objective was to use time-driven activity-based costing (TDABC) methodology to determine whether surgeons' case volume influenced the true intraoperative costs of ACDFs performed at our institution.

SUMMARY OF BACKGROUND DATA

Successful participation in emerging reimbursement models, such as bundled payments, requires an understanding of true intraoperative costs, as well as the modifiable drivers of those costs. Certain surgeons may have cost profiles that are favorable for these "at-risk" reimbursement models, while other surgeons may not.

METHODS

Total cost was divided into direct and indirect costs. Individual costs were obtained by direct observation, electronic medical records, and through querying multiple departments (business operations, sterile processing, plant operations, and pharmacy). Timestamps for all involved personnel and material resources were documented. All surgeons performing ACDFs at our primary and affiliated hospital sites from 2017 to 2022 were divided into four volume-based cohorts: 1-9 cases (n=10 surgeons, 38 cases), 10-29 cases (n=7 surgeons, 126 cases), 30-100 cases (n=3 surgeons, 234 cases), and > 100 cases (n=2 surgeons, 561 cases).

RESULTS

The average total intraoperative cost per case was $7,116 +/- $2,945. The major cost contributors were supply cost ($4,444, 62.5%) and personnel cost ($2,417, 34.0%). A generalized linear mixed model utilizing Poisson distribution was performed with the surgeon as a random effect. Surgeons performing 1-9 total cases, 10-29 cases, and 30-100 cases had increased total cost of surgery (P < 0.001; P < 0.001; and P<0.001, respectively) compared to high-volume surgeons (> 100 cases). Among all volume cohorts, high-volume surgeons also had the lowest mean supply cost, personnel cost, and operative times, while the opposite was true for the lowest-volume surgeons (1-9 cases).

CONCLUSION

It is becoming increasingly important for hospitals to identify modifiable sources of variation in cost. We demonstrate a novel use of TDABC for this purpose.

LEVEL OF EVIDENCE

Level-III.

What is the Marginal Cost of Using Robot Assistance or Navigation for Transforaminal Lumbar Interbody Fusion? A Time-Driven Activity-Based Cost Analysis

BACKGROUND AND OBJECTIVE

Our primary objective was to compare the marginal intraoperative cost of 3 different methods for pedicle screw placement as part of transforaminal lumbar interbody fusions (TLIFs). Specifically, we used time-driven activity-based costing to compare costs between robot-assisted TLIF (RA-TLIF), TLIF with intraoperative navigation (ION-TLIF), and freehand (non-navigated, nonrobotic) TLIF.

METHODS

Total cost was divided into direct and indirect costs. We identified all instances of RA-TLIF (n = 20), ION-TLIF (n = 59), and freehand TLIF (n = 233) from 2020 to 2022 at our institution. Software was developed to automate the extraction of all intraoperatively used personnel and material resources from the electronic medical record. Total costs were determined through a combination of direct observation, electronic medical record extraction, and interdepartmental collaboration (business operations, sterile processing, pharmacy, and plant operation departments). Multivariable linear regression analysis was performed to compare costs between TLIF modalities, accounting for patient-specific factors as well as number of levels fused, surgeon, and hospital site.

RESULTS

The average total intraoperative cost per case for the RA-TLIF, ION-TLIF, and freehand TLIF cohorts was $24 838 ± $10 748, $15 991 ± $6254, and $14 498 ± $6580, respectively. Regression analysis revealed that RA-TLIF had significantly higher intraoperative cost compared with both ION-TLIF (β-coefficient: $7383 ± $1575, P < .001) and freehand TLIF (β-coefficient: $8182 ± $1523, P < .001). These cost differences were primarily driven by supply cost. However, there were no significant differences in intraoperative cost between ION-TLIF and freehand TLIF (P = .32).

CONCLUSION

We demonstrate a novel use of time-driven activity-based costing methodology to compare different modalities for executing the same type of lumbar fusion procedure. RA-TLIF entails significantly higher supply cost when compared with other modalities, which explains its association with higher total intraoperative cost. The use of ION, however, does not add extra expense compared with freehand TLIF when accounting for confounders. This might have implications as surgeons and hospitals move toward bundled payments.

Are We Finally Ready for Total Joint Replacement of the Spine? An Extension of Charnley's Vision

Professor Sir John Charnley has been rightfully hailed as a visionary innovator for conceiving, designing, and validating the Operation of the Century-the total hip arthroplasty. His groundbreaking achievement forever changed the orthopedic management of chronically painful and dysfunctional arthritic joints. However, the well-accepted surgical approach of completely removing the diseased joint and replacing it with a durable and anatomically based implant never translated to the treatment of the degenerated spine. Instead, decompression coupled with fusion evolved into the workhorse intervention. In this commentary, the authors explore the reasons why arthrodesis has remained the mainstay over arthroplasty in the field of spine surgery as well as discuss the potential shift in the paradigm when it comes to treating degenerative lumbar disease.

Transforaminal Contrast Injection Before Computed Tomography-Guided Lateral Endoscopic Lumbar Diskectomy Improves Visualization of Exiting Nerve Root

BACKGROUND AND OBJECTIVES

Percutaneous endoscopic lumbar diskectomy (PELD) is an effective, minimally invasive method for removal of lateral lumbar disk herniations. This minimally invasive technique can be applied with high success and lead to faster recovery than traditional methods. Unfortunately, adoption of these techniques in the United States has been slow. A significant barrier to using this technique is often an inability to completely visualize relevant anatomy and increased operative times. In this article, we describe a technique using computed tomography (CT) guidance in conjunction with a neurogram to perform a PELD. We detail the steps in the technique and its advantages to the surgeon performing it.

METHODS

After a patient is placed supine on a table, a transforaminal injection of contrast is performed under fluoroscopic guidance. Then, after sterilizing and draping in a normal fashion, an intraoperative CT scan is taken with a reference frame in place. During the procedure, this allows for the CT guidance to have the exiting nerve root clearly outlined.

RESULTS

This procedure was successfully performed in a single patient, allowing greater visualization of the exiting nerve root during a difficult revision PELD case. No complications were experienced.

CONCLUSION

A novel technique using a neurogram with CT guidance during a PELD was used to assist with identification of anatomy and decompression of the exiting nerve root. This technique was used without complications.

Does Body Mass Index Influence Intraoperative Costs and Operative Times for Anterior Cervical Discectomy and Fusion? A Time-Driven Activity-Based Costing Analysis

OBJECTIVE

Spine surgeons are often unaware of drivers of cost variation for anterior cervical discectomy and fusion (ACDF). We used time-driven activity-based costing to assess the relationship between body mass index (BMI), total cost, and operating room (OR) times for ACDFs.

METHODS

Total cost was divided into direct and indirect costs. Individual costs were obtained by direct observation, electronic medical records, and through querying multiple departments. Timestamps for all involved personnel and material resources were documented. Total intraoperative costs were estimated for all ACDFs from 2017 to 2022. All patients were categorized into distinct BMI-based cohorts. Linear regression models were performed to assess the relationship between BMI, total cost, and OR times.

RESULTS

A total of 959 patients underwent ACDFs between 2017 and 2022. The average age and BMI were 58.1 ± 11.2 years and 30.2 ± 6.4 kg/m2, respectively. The average total intraoperative cost per case was $7120 ± $2963. Multivariable regression analysis revealed that BMI was not significantly associated with total cost (P = 0.36), supply cost (P = 0.39), or personnel cost (P = 0.20). Higher BMI was significantly associated with increased time spent in the OR (P = 0.018); however, it was not a significant factor for the duration of surgery itself (P = 0.755). Rather, higher BMI was significantly associated with nonoperative OR time (P < 0.001).

CONCLUSIONS

Time-driven activity-based costing is a feasible and scalable methodology for understanding the true intraoperative costs of ACDF. Although higher BMI was not associated with increased total cost, it was associated with increased preparatory time in the OR.

What is the Marginal Intraoperative Cost of Using an Exoscope or Operative Microscope for Anterior Cervical Discectomy and Fusion? A Time-Driven Activity-Based Cost Analysis

OBJECTIVE

Our primary objective was to compare the intraoperative costs of 3 different surgical visualization techniques for anterior cervical discectomy and fusion (ACDF). Specifically, we used time-driven activity-based costing (TDABC) methodology to compare costs between ACDFs performed with operative microscopes (OM-ACDF), exoscopes (EX-ACDF), and loupes (loupes-ACDF).

METHODS

Total cost was divided into direct and indirect costs. Individual costs were obtained by direct observation, electronic medical records, and through querying multiple departments (business operations, sterile processing, plant operations, and pharmacy). Timestamps for all involved personnel and material resources were documented. We identified all instances of loupes-ACDF (n = 882), EX-ACDF (n = 26), and OM-ACDF (n = 52) performed at our institution. We performed multivariable linear regression analyses to compare costs between these modalities, accounting for patient-specific factors as well as number of levels fused, surgeon, and hospital site.

RESULTS

The average total intraoperative costs per loupes-ACDF, EX-ACDF, and OM-ACDF cases were $7081 +/- $2,942, $7951 +/- $3,488, and $6557 +/- $954, respectively. Regression analysis revealed no difference in intraoperative cost between loupes-ACDF and EX-ACDF (P = 0.717), loupes-ACDF and OM-ACDF (0.954), or OM-ACDF and EX-ACDF (0.217). On a more granular level, however, EX-ACDF was associated with increased cost of consumables, including drapes, compared to both OM-ACDF (β-coefficient: $369 +/- $121, P = 0.002) and loupes-ACDF (β-coefficient: $284 +/- $86, P = 0.001).

CONCLUSIONS

Although hospitals may be aware of the purchasing fees associated with microscopes and exoscopes, there is no clear documentation of how these technologies affect intraoperative cost. We demonstrate a novel use of TDABC for this purpose.

Smartphone-based activity tracking for spine patients: Current technology and future opportunities

Activity trackers and wearables allow accurate determination of physical activity, basic vital parameters, and tracking of complex medical conditions. This review attempts to provide a roadmap for the development of these applications, outlining the basic tools available, how they can be combined, and what currently exists in the marketplace for spine patients. Various types of sensors currently exist to measure distinct aspects of user movement. These include the accelerometer, gyroscope, magnetometer, barometer, global positioning system (GPS), Bluetooth and Wi-Fi, and microphone. Integration of data from these sensors allows detailed tracking of location and vectors of motion, resulting in accurate mobility assessments. These assessments can have great value for a variety of healthcare specialties, but perhaps none more so than spine surgery. Patient-reported outcomes (PROMs) are subject to bias and are difficult to track frequently - a problem that is ripe for disruption with the continued development of mobility technology. Currently, multiple mobile applications exist as an extension of clinical care. These include Manage My Surgery (MMS), SOVINITY-e-Healthcare Services, eHealth System, Beiwe Smartphone Application, QS Access, 6WT, and the TUG app. These applications utilize sensor data to assess patient activity at baseline and postoperatively. The results are evaluated in conjunction with PROMs. However, these applications have not yet exploited the full potential of available sensors. There is a need to develop smartphone applications that can accurately track the functional status and activity of spine patients, allowing a more quantitative assessment of outcomes, in contrast to legacy PROMs.

Comparison of 5-Item and 11-Item Modified Frailty Index as Predictors of Functional Independence in Patients With Spinal Cord Injury

STUDY DESIGN

Retrospective Cohort Study.

INTRODUCTION

The 11-item modified Frailty index (mFI-11) by the ACS-NSQIP database was used to predict which patients are high risk for complications and inpatient mortality. ACS-NSQIP now has switched to the 5-item MFI. However, there are no studies on how these frailty indices fare against each other and their prognostic value of functional independence in patients with spinal cord injury (SCI).

OBJECTIVE

To compare the mFI-5 and mFI-11 in order to standardize frailty assessment in the SCI population.

METHODS

Retrospective analysis of 272,174 patients with SCI from 2010 to 2020 from the Pennsylvania Trauma Systems Foundation (PTSF) registry. Multivariable logistic regression was used to determine the predictive value of mFI for functional independence as determined by locomotion and transfer mobility.

RESULTS

A total of 1907 patients were included with a mean age of 46.9 ± 15.1 years. The 3 most common MFI factors were hypertension (32.2%), diabetes mellitus (13.7%) and chronic obstructive pulmonary disease (8.5%). Multivariable logistic regression analyses using MFI-5 and MFI-11 showed that a higher frailty score in MFI-5 (OR 1.375, P < .001) and in MFI-11 (OR 1.366, P < .001) were each predictive of poor functional status at discharge. ROC curves for the MFI-5 (AUC = .818, P < .001) and MFI-11 (AUC = .819, P < .001) demonstrated excellent diagnostic accuracy.

CONCLUSION

The new MFI-5 is equivalent to its predecessor, the MFI-11, and predictive of functional outcomes in patients with SCI. MFI-5 can serve as the preferred frailty index at the point of care and in research contexts.

When Does Intervention End and Surgery Begin? The Role of Interventional Pain Management in the Treatment of Spine Pathology

PURPOSE OF REVIEW

Recent advances in the field of interventional pain management (IPM) involve minimally invasive procedures such as percutaneous lumbar decompression, interspinous spacer placement, interspinous-interlaminar fusion and sacroiliac joint fusion. These developments have received pushback from surgical professional societies, who state spinal instrumentation and arthrodesis should only be performed by spine surgeons. The purpose of this review is to evaluate the validity of this claim. A literature search was conducted on Google Scholar and PubMed databases. Articles were included which examined IPM in the following contexts: credentialing and procedural privileging guidelines, fellowship training and education, and procedural outcomes compared to those of surgical specialties. Our primary research question is: "Should interventionalists be performing decompression and fusion procedures?".

FINDINGS

Advanced percutaneous spine procedures are not universally incorporated into pain fellowship curriculums. Trainees attempt to compensate for these deficiencies through industry-led training, which has been criticized for lacking central regulation. There is also a paucity of studies comparing procedural outcomes between surgeons and interventionalists for complex spine procedures, including decompression and fusion. Pain fellowship curriculums have not kept pace with some of procedural advancements within the field. Interventionalists are also not trained to manage potential complications of spinal instrumentation and arthrodesis, which has been recognized as an essential requirement for procedural privileging. Decompression and fusion may therefore be outside the scope of an interventionalist's practice.

Development of a Systems Medicine Approach to Spinal Cord Injury

Traumatic spinal cord injury (SCI) causes a sudden onset multi-system disease, permanently altering homeostasis with multiple complications. Consequences include aberrant neuronal circuits, multiple organ system dysfunctions, and chronic phenotypes such as neuropathic pain and metabolic syndrome. Reductionist approaches are used to classify SCI patients based on residual neurological function. Still, recovery varies due to interacting variables, including individual biology, comorbidities, complications, therapeutic side effects, and socioeconomic influences for which data integration methods are lacking. Infections, pressure sores, and heterotopic ossification are known recovery modifiers. However, the molecular pathobiology of the disease-modifying factors altering the neurological recovery-chronic syndrome trajectory is mainly unknown, with significant data gaps between intensive early treatment and chronic phases. Changes in organ function such as gut dysbiosis, adrenal dysregulation, fatty liver, muscle loss, and autonomic dysregulation disrupt homeostasis, generating progression-driving allostatic load. Interactions between interdependent systems produce emergent effects, such as resilience, that preclude single mechanism interpretations. Due to many interacting variables in individuals, substantiating the effects of treatments to improve neurological outcomes is difficult. Acute injury outcome predictors, including blood and cerebrospinal fluid biomarkers, neuroimaging signal changes, and autonomic system abnormalities, often do not predict chronic SCI syndrome phenotypes. In systems medicine, network analysis of bioinformatics data is used to derive molecular control modules. To better understand the evolution from acute SCI to chronic SCI multi-system states, we propose a topological phenotype framework integrating bioinformatics, physiological data, and allostatic load tested against accepted established recovery metrics. This form of correlational phenotyping may reveal critical nodal points for intervention to improve recovery trajectories. This study examines the limitations of current classifications of SCI and how these can evolve through systems medicine.

Bulbocavernosus Reflex Has No Prognostic Features During the Acute Evaluation of Spinal Cord Injuries

The bulbocavernosus reflex (BCR) has been used during the initial evaluation of a spinal cord injury patient as a metric to determine prognosis and whether the patient is in "spinal shock." This reflex has been less utilized over the last decade, and therefore a review was performed to assess the value of BCR in patient prognosis. The North American Clinical Trials Network (NACTN) for Spinal Cord Injury (SCI) is a consortium of tertiary medical centers that includes a prospective SCI registry. The NACTN registry data was analyzed to evaluate the prognostic implication of the BCR during the initial evaluation of a spinal cord injury patient. SCI patients were divided into those with an intact or absent BCR during their initial evaluation. Associations of participants' descriptors and neurological status on follow-up were performed, followed by associations with the presence of a BCR. A total of 769 registry patients with recorded BCRs were included in the study. The median age was 49 years (32-61 years), and the majority were male (n = 566, 77%) and white (n = 519, 73%). Among included patients, high blood pressure was the most common comorbidity (n = 230, 31%). Cervical spinal cord injury was the most common (n = 470, 76%) with fall (n = 320, 43%) being the most frequent mechanism of injury. BCR was present in 311 patients (40.4%), while 458 (59.6%) had a negative BCR within 7 days of injury or before surgery. At 6 months post-injury, 230 patients (29.9%) followed up, of which 145 had a positive BCR, while 85 had a negative BCR. The presence/absence of BCR was significantly different in patients with cervical (p = 0.0015) or thoracic SCI (p = 0.0089), or conus medullaris syndrome (p = 0.0035), and in those who were American Spinal Injury Association Impairment Scale grade A (p = 0.0313). No significant relationship was observed between BCR results and demographics, AIS grade conversion, motor score changes (p = 0.1669), and changes in pin prick (p = 0.3795) and light touch scores (p = 0.8178). In addition, cohorts were not different in surgery decision (p = 0.7762) and injury to surgery time (p = 0.0681). In our review of the NACTN spinal cord registry, the BCR did not provide prognostic utility in the acute evaluation of spinal cord injury patients. Therefore, it should not be used as a reliable marker for predicting neurological outcomes post-injury.

The Feasibility of 3D Intraoperative Navigation in Lateral Lumbar Interbody Fusion: Perioperative Outcomes, Accuracy of Cage Placement and Radiation Exposure

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To evaluate perioperative outcomes, accuracy of cage placement and radiation exposure in lateral lumbar interbody fusion (LLIF) using 3D intraoperative navigation (ION), compared to conventional 2D fluoroscopy only.

METHODS

The perioperative outcomes and accuracy of cage placement were examined in all patients who underwent LLIF using ION (ION group) or fluoroscopy only (non-ION group) by a single surgeon. The radiation exposure was examined in patients who underwent stand-alone LLIF.

RESULTS

A total of 87 patients with 154 levels (ION 49 patients with 79 levels/ non-ION 38 patients with 75 levels) were included. There were no significant differences in operative time (ION 143.5 min vs. non-ION 126.0 min, P = .406), time from induction end to surgery start (ION 31.0 min vs. non-ION 31.0 min, P = .761), estimated blood loss (ION 37.5 ml vs. non-ION 50.0 ml, P = .351), perioperative complications (ION 16.3% vs. non-ION 7.9%, P = .335) and length of stay (ION 50.6 hours vs. non-ION 41.7 hours, P = .841). No significant difference was found in the accuracy of cage placement (P = .279). ION did not significantly increase total radiation dose (ION 51.0 mGy vs. non-ION 47.4 mGy, P = .237) and tended to reduce radiation dose during the procedure (ION 32.2 mGy vs. non-ION 47.4 mGy, P = .932).

CONCLUSIONS

The perioperative outcomes, accuracy of cage placement and radiation exposure in LLIF using ION were comparable to those using fluoroscopy only. The use of ION in LLIF was feasible, safe and accurate and may reduce radiation dose to the surgeon and surgical team.

A Multi-Disciplinary Review of Time-Driven Activity-Based Costing: Practical Considerations for Spine Surgery

STUDY DESIGN

A multi-disciplinary review.

OBJECTIVES

To provide a roadmap for implementing time-driven activity-based costing (TDABC) for spine surgery. This is achieved by organizing and scrutinizing publications in the spine, neurosurgical, and orthopedic literature which utilize TDABC and related methodologies.

METHODS

PubMed and Google Scholar were searched for relevant articles. The articles were selected by two independent researchers. After article selection, data was extracted and summarized into research domains. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) systematic review process was followed.

RESULTS

Of the 524 articles screened, thirty-five articles met the inclusion criteria. Each included article was examined and reviewed to define the primary research question and objective. Comparing different procedures was the most common primary objective. Direct observation along with one other strategy (surveys, interviews, surgical database, or EMR) was most commonly employed during process map development. Across all surgical subspecialties (spine, neurologic, and orthopedic surgery), costs were divided into direct cost, indirect cost, cost to patient, and total costs. The most commonly calculated direct costs included personnel and supply costs. Facility costs, hospital overhead costs, and utilities were the most commonly calculated indirect costs. Transportation costs and parental lost wages were considered when calculating cost to patient. The total cost was a sum of direct costs, indirect costs, and costs to the patient.

CONCLUSION

TDABC provides a common platform to accurately estimate costs of care delivery. Institutions embarking on TDABC for spine surgery should consider the breadth of methodologies highlighted in this review to determine which type of calculations are appropriate for their practice.

Multimodality Intraoperative Neuromonitoring in Lateral Lumbar Interbody Fusion: A Review of Alerts in 628 Patients

STUDY DESIGN

Retrospective review of private neuromonitoring databases.

OBJECTIVES

To review neuromonitoring alerts in a large series of patients undergoing lateral lumbar interbody fusion (LLIF) and determine whether alerts occurred more frequently when more lumbar levels were accessed or more frequently at particular lumbar levels.

METHODS

Intraoperative neuromonitoring (IONM) databases were reviewed and patients were identified undergoing LLIF between L1 and L5. All cases in which at least one IONM modality was used (motor evoked potentials (MEP), somatosensory evoked potentials (SSEP), evoked electromyography (EMG)) were included in this study. The type of IONM used and incidence of alerts were collected from each IONM report and analyzed. The incidence of alerts for each IONM modality based on number of levels at which at LLIF was performed and the specific level an LLIF was performed were compared.

RESULTS

A total of 628 patients undergoing LLIF across 934 levels were reviewed. EMG was used in 611 (97%) cases, SSEP in 561 (89%), MEP in 144 (23%). The frequency of IONM alerts for EMG, SSEP and MEPs did not significantly increase as the number of LLIF levels accessed increased. No EMG, SSEP, or MEP alerts occurred at L1-L2. EMG alerts occurred in 2-5% of patients at L2-L3, L3-L4, and L4-L5 and did not significantly vary by level (P = .34). SSEP and MEP alerts occurred more frequently at L4-L5 versus L2-L3 and L3-L4 (P < .03).

CONCLUSIONS

IONM may provide the greatest utility at L4-L5, particularly MEPs, and may not be necessary for more cephalad LLIF procedures such as at L1-L2.

Technical Aspects of Intra-Operative Ultrasound for Spinal Cord Injury and Myelopathy: A Practical Review

OBJECTIVES

To compile intra-operative techniques, established imaging parameters, available equipment and software, and clinical applications of intraoperative ultrasound imaging (IOUSI) for spinal cord injury (SCI) and myelopathy.

METHODS

PubMed and Google Scholar were searched for relevant articles. The articles were reviewed and selected by 2 independent researchers. After article selection, data were extracted and summarized into research domains. PRISMA systematic review process was followed.

RESULTS

Of the 2477 articles screened, 16 articles met the inclusion criteria. In patients with SCI and myelopathy, common quantitative measurements obtained using IOUSI were noted: 1) ultrasound elastography, 2) midsagittal anteroposterior diameter, 3) transverse, 4) transverse diameter, 5) maximum spinal cord compression, and 6) compression ratioTo ensure adequate decompression and to look for residual compression, the lateral and the craniocaudal margins of the laminectomy site were inspected in both axial and sagittal planes. In instances where quantitative assessment was not possible, cord decompression and degree of residual compression were gauged by inspecting the interface between the ventral border of the spinal cord and any potentially compressive elements, and by searching for symmetric and rhythmic cerebrospinal fluid pulsations. Use of contrast-enhanced ultrasoundand molecular imaging are additional advances in objective assessments for SCI and myelopathy.

CONCLUSIONS

This review outlines the potential of IOUSI in patients presenting with SCI and myelopathy. Moreover, by identifying potential for inter-operator variability in certain subjective measurements, we illustrate the need for further research to quantify and standardize those assessments.

Practical answers to frequently asked questions in minimally invasive lumbar spine surgery

BACKGROUND CONTEXT

Surgical counseling enables shared decision-making (SDM) by improving patients' understanding.

PURPOSE

To provide answers to frequently asked questions (FAQs) in minimally invasive lumbar spine surgery.

STUDY DESIGN

Retrospective review of prospectively collected data.

PATIENT SAMPLE

Patients who underwent primary tubular minimally invasive lumbar spine surgery in form of transforaminal lumbar interbody fusion (MI-TLIF), decompression alone, or microdiscectomy and had a minimum of 1-year follow-up.

OUTCOME MEASURES

(1) Surgical (radiation exposure and intraoperative complications) (2)Immediate postoperative (length of stay [LOS] and complications) (3) Clinical outcomes (Visual Analog Scale- back and leg, VAS; Oswestry Disability Index, ODI; 12-Item Short Form Survey Physical Component Score, SF-12 PCS; Patient-Reported Outcomes Measurement Information System Physical Function, PROMIS PF; Global Rating Change, GRC; return to activities; complications/reoperations) METHODS: The outcome measures were analyzed to provide answers to ten FAQs that were compiled based on the authors' experience and a review of literature. Changes in VAS back, VAS leg, ODI, and SF-12 PCS from preoperative values to the early (<6 months) and late (>6 months) postoperative time points were analyzed with Wilcoxon Signed Rank Tests. % of patients achieving minimal clinically important difference (MCID) for these patient-reported outcome measures (PROMs) at the two time points was evaluated. Changes in PROs from preoperative values too early (<6 months) and late (≥6 months) postoperative time points were analyzed within each of the three groups. Percentage of patients achieving MCID was also evaluated.

RESULTS

Three hundred sixty-six patients (104 TLIF, 147 decompression, 115 microdiscectomy) were included. The following FAQs were answered: (1) Will my back pain improve? Most patients report improvement by >50%. About 60% of TLIF, decompression, and microdiscectomy patients achieved MCID at ≥6 months. (2) Will my leg pain improve? Most patients report improvement by >50%. 56% of TLIF, 67% of decompression, and 70% of microdiscectomy patients achieved MCID at ≥6 months. (3) Will my activity level improve? Most patients report significant improvement. Sixty-six percent of TLIF, 55% of decompression, and 75% of microdiscectomy patients achieved MCID for SF-12 PCS. (4) Is there a chance I will get worse? Six percent after TLIF, 14% after decompression, and 5% after microdiscectomy. (5) Will I receive a significant amount of radiation? The radiation exposure is likely to be acceptable and nearly insignificant in terms of radiation-related risks. (6) What is the likelihood that I will have a complication? 17.3% (15.4% minor, 1.9% major) for TLIF, 10% (9.3% minor and 0.7% major) for decompression, and 1.7% (all minor) for microdiscectomy (7) Will I need another surgery? Six percent after TLIF, 16.3% after decompression, 13% after microdiscectomy. (8) How long will I stay in the hospital? Most patients get discharged on postoperative day one after TLIF and on the same day after decompression and microdiscectomy. (9) When will I be able to return to work? >80% of patients return to work (average: 25 days after TLIF, 14 days after decompression, 11 days after microdiscectomy). (10) Will I be able to drive again? >90% of patients return to driving (average: 22 days after TLIF, 11 days after decompression, 14 days after microdiscectomy).

CONCLUSIONS

These concise answers to the FAQs in minimally invasive lumbar spine surgery can be used by physicians as a reference to enable patient education.

Rating Spine Surgeons: Physician Review Websites Versus a Patient-reported Outcomes-derived Ranking

STUDY DESIGN

This was an observational study.

OBJECTIVES

This study aims to determine the correlation between patient-reported outcomes (PROs) pulled from a national spine registry and physician ratings from physician review websites (PRWs).

SUMMARY OF BACKGROUND DATA

PRWs are frequently utilized by patients to make health care decisions; however, many PRWs appear to incorporate subjective experiences unrelated to a surgeon's clinical performance into ratings. As such, their utility as a health care decision-making tool remains unclear.

MATERIALS AND METHODS

This study evaluated 8834 patients from the Quality Outcomes Database (QOD) who underwent 1-level elective lumbar spine surgery. The lumbar module of QOD was queried to rank 124 surgeons using PROs (Oswestry Disability Index, EuroQOL, Numerical Rating Scale-back/leg pain, and patient satisfaction). The QOD PRO-ranking system was compared against PRWs including Healthgrades, Vitals, WebMD, and Google. The Spearman correlation coefficients, Kruskal-Wallis tests, and multiple linear regression models were used for statistical comparison. The primary outcome was the correlation between PRW scores and PROs.

RESULTS

Surgeon PRO-derived ranking showed high intercorrelational congruence with coefficients between the 3 PROs (Oswestry Disability Index, EuroQOL, Numerical Rating Scale back/leg) ranging between 0.70 and 0.88. Low correlations were observed between PRO-derived rankings and PRWs, ranging from 0.23 to 0.37. Healthgrades performed most similarly to PRO-derived rankings, correlating best with patient satisfaction, though the correlation was low (ρ=0.37).

CONCLUSIONS

While PRWs are often used to evaluate surgeon competency, these results demonstrate they poorly correlate with a surgeon's clinical ability measured by PROs. PRWs should be used with caution when making health care decisions by patients, payers, and administrators.

LEVEL OF EVIDENCE

Level III.

Factors Causing Delay in Discharge in Patients Eligible for Ambulatory Lumbar Fusion Surgery

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To analyze the postoperative factors that led delayed discharge in patients who would have been eligible for ambulatory lumbar fusion (ALF).

SUMMARY OF BACKGROUND DATA

Assessing postoperative inefficiencies is vital to increase the feasibility of ALF.

MATERIALS AND METHODS

Patients who underwent single-level minimally invasive transforaminal lumbar interbody fusion and would have met the eligibility criteria for ALF were included. Length of stay (LOS); time in postanesthesia recovery unit (PACU); alertness and neurological examination, and pain scores at three and six hours; type of analgesia; time to physical therapy (PT) visit; reasons for PT nonclearance; time to per-oral (PO) intake; time to voiding; time to readiness for discharge were assessed. Time taken to meet each discharge criterion was calculated. Multiple regression analyses were performed to study the effect of variables on postoperative parameters influencing discharge.

RESULTS

Of 71 patients, 4% were discharged on the same day and 69% on postoperative day 1. PT clearance was the last-met discharge criterion in 93%. Sixty-six percent did not get PT evaluation on the day of surgery. Seventy-six percent required intravenous opioids and <60% had adequate pain control. Twenty-six percent had orthostatic intolerance. The median postoperative LOS was 26.9 hours, time in PACU was 4.2 hours, time to PO intake was 6.5 hours, time to first void was 6.3 hours, time to first PT visit was 17.7 hours, time to PT clearance was 21.8 hours, and time to discharge readiness was 21.9 hours. Regression analysis showed that time to PT clearance, time to PO intake, time to voiding, time in PACU, and pain score at three hours had a significant effect on LOS.

CONCLUSIONS

Unavailability of PT, surgery after 1  pm , orthostatic intolerance, inadequate pain control, prolonged PACU stay, and long feeding and voiding times were identified as modifiable factors preventing same-day discharge.

LEVEL OF EVIDENCE

4.

Advanced Technologies for Outpatient Lumbar Fusion: Barriers and Opportunities

BACKGROUND

In recent years, there has been increasing interest in outpatient spine surgery. Minimally invasive techniques have created an opportunity for ambulatory lumbar fusion, and these techniques increasingly involve advanced technologies such as navigation and robotics.

OBJECTIVE

To explore the barriers, advantages, and future predictions for such technology in the context of outpatient lumbar fusions.

METHODS

This is a narrative review of studies examining the advantages, limitations, and cost-effectiveness of navigation and spinal robotics in conjunction with the outcomes and costs of outpatient lumbar fusion.

RESULTS

Outpatient lumbar fusion is a growing trend with ample evidence of its safety, favorable patient outcomes, and cost savings. Navigation and spinal robotics are associated with improved instrumentation accuracy and fewer complications, and the long-term cost savings can make these technologies financially practical in the outpatient setting. Future capabilities with robotics will only increase their value.

CONCLUSIONS

Advanced technologies such as navigation and robotics are strategic long-term investments in the context of outpatient lumbar fusion.

CLINICAL RELEVANCE

The favorable outcomes and costs associated with navigation and robotics will be relevant to any spine surgeon interested in developing an outpatient lumbar fusion program.

LEVEL OF EVIDENCE: 5

Cervical Disc Replacement for Radiculopathy Versus Myeloradiculopathy: An MCID Analysis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The aim was to compare the minimally clinically important difference (MCID) across multiple patient-reported outcomes (PROs) in patients undergoing cervical disc replacement (CDR) for cervical spondylotic radiculopathy versus myeloradiculopathy.

SUMMARY OF BACKGROUND DATA

To date, a limited number of studies have demonstrated mostly similar results in patients with cervical spondylotic radiculopathy or myeloradiculopathy undergoing CDR. However, each of these previous studies have focused on statistically significant differences, which may not correlate with patient perceived improvements in outcomes or success.

METHODS

Patients who underwent 1 or 2-level CDR with radiculopathy versus myeloradiculopathy were identified, and prospectively collected data was retrospectively reviewed. Demographic variables, preoperative diagnosis, and operative variables were collected for each patient. The following PROs were prospectively collected: Neck Disability Index (NDI), visual analog scale (VAS)-Neck, VAS-Arm, Short Form-12 Health Survey (SF-12) Physical Component Score (PCS), SF-12 Mental Component Score (MCS), PROMIS Physical Function (PF). An MCID analysis of PROs for each diagnosis group was performed and the percentage of patients achieving the MCID was compared between the two diagnosis groups.

RESULTS

Eight-five patients, of which 56% had radiculopathy and 44% had myeloradiculopathy. MCID analysis demonstrated that at 6-week, 12-week, and final postoperative follow-up there was no significant difference in the percentage of patients with radiculopathy or myeloradiculopathy achieving the MCID for each PRO assessed. In both diagnosis groups the percentage of patients achieving the MCID for each PRO continued to increase from the 6-week to final postoperative follow-up except for the SF-12 MCS in patients with myeloradiculopathy.

CONCLUSIONS

The percentage of patients achieving the MCID was not significantly different at each postoperative period assessed in the radiculopathy and myeloradiculopathy groups treated with CDR. In addition, the percentage of patients achieving the MCID continued to increase from 6 weeks to final follow-up in both groups for almost all PROs assessed.

Clinical and Cost-Effectiveness of Lumbar Interbody Fusion Using Tritanium Posterolateral Cage (vs. Propensity-Matched Cohort of PEEK Cage)

Introduction

Surgical management of degenerative lumbar spine disorders is effective at improving patient pain, disability, and quality of life; however, obtaining a durable posterolateral fusion after decompression remains a challenge. Interbody fusion technologies are viable means of improving fusion rates in the lumbar spine, specifically various graft materials including autograft, structural allograft, titanium, and polyether ether ketone. This study assesses the effectiveness of Tritanium posterolateral cage in the treatment of degenerative disk disease.

Methods

Nearest-neighbor 1:1 matched control transforaminal lumbar interbody fusion with PEEK vs. Tritanium posterior lumbar (PL) cage interbody fusion patients were identified using propensity scoring from patients that underwent elective surgery for degenerative disk diseases. Line graphs were generated to compare the trajectories of improvement in patient-reported outcomes (PROs) from baseline to 3 and 12 months postoperatively. The nominal data were compared via the χ² test, while the continuous data were compared via Student's t-test.

Results

The two groups had no difference regarding either the 3- or 12-month Euro-Qol-5D (EQ-5D), numeric rating scale (NRS) leg pain, and NRS back pain; however, the Tritanium interbody cage group had better Oswestry Disability Index (ODI) scores compared to the control group of the PEEK interbody cage at both 3 and 12 months (p=0.013 and 0.048).

Conclusions

Our results indicate the Tritanium cage is an effective alternative to the previously used PEEK cage in terms of PROs, surgical safety, and radiological parameters of surgical success. The Tritanium cohort showed better ODI scores, higher fusion rates, lower subsidence, and lower indirect costs associated with surgical management, when compared to the propensity-matched PEEK cohort.

Surface Navigation and the Influence of Navigation on MIS Surgery

STUDY DESIGN

Literature review.

OBJECTIVES

To review the evidence for surface-based navigation in minimally-invasive spine surgery (MIS), provide an outline for its workflow, and present a wide range of MIS case examples in which surface-based navigation may be advantageous.

METHODS

A comprehensive review of the literature and compilation of findings related to surface-based navigation in MIS was performed. Workflow and case examples utilizing surface-based navigation were described.

RESULTS

The nascent literature regarding surface-based intraoperative navigation (ION) in spine surgery is encouraging and initial studies have shown that surface-based navigation can allow for accurate pedicle screw placement and decreased operative time, fluoroscopy time, and radiation exposure when compared to traditional fluoroscopic imaging. Surface-based navigation may be particularly useful in MIS cervical and lumbar decompressions and MIS lumbar instrumentation cases.

CONCLUSIONS

Overall, it is possible that surface-based ION will become a mainstay in the armamentarium of enabling technologies utilized by minimally-invasive spine surgeons, but further studies are needed assessing its accuracy, complications, and cost-effectiveness.

A Review of Endoscopic Spine Surgery: Decompression for Radiculopathy

PURPOSE OF REVIEW

With this manuscript the authors sought to write a succinct review of the origins, as well as the latest advancements in endoscopic spine surgery to serve as a reference frame for physicians looking to learn this approach.

RECENT FINDINGS

At its infancy, the indications for posterolateral and transforaminal endoscopic decompression remained narrow, which prevented the procedure from gaining rapid traction during those days. However, more recently the tides have turned and an increasing number of surgeons are starting to adopt this technique given all its advantages. With the advent of higher quality camera systems and instruments, indications to use a minimally invasive option have gotten significantly broader. The most basic indication for the use of this technology is a soft disc herniation causing compromise of a neural structure that has failed to be managed successfully with non-surgical therapies. The use of endoscopic techniques provides significant advantages to patient outcomes and patient recovery. Endoscopic procedures should not be used as a blanket approach to nerve root decompression, as they certainly have limitations. Most contraindications to this procedure are relative and serve mostly as points to consider when selecting the methods to address neural compression. As these techniques become more widely accepted, we expect its reach and indications to continue to broaden and diversify. The full integration of navigation technologies will likely leapfrog this procedure into the mainstream use.

Perioperative Modifications to the Open TLIF Provide Comparable Short-term Outcomes to the MIS-TLIF

STUDY DESIGN

This study is a retrospective review of patients' charts and data from longitudinally collected clinical outcomes and opioid use.

OBJECTIVE

In the current study, we aim to compare short-term outcomes data for 139 Open transforaminal interbody fusion (TLIF) patients to recently published data for tubular and endoscopic MIS-TLIF.

BACKGROUND CONTEXT

In response to the downsides associated with Open TLIF, such as large incision, blood loss, delayed ambulation, prolonged hospitalization, and opioid-reliance, spine surgeons developed tubular retractor based "minimally-invasive" TLIF. However, the traditional Open TLIF retains its significance in terms of providing successful fusion and improved patient-reported outcomes (PROs).

METHODS

We adapted several techniques with an aim to improve short-term outcomes for our Open TLIF patients that combined extensive perioperative counselling, an emphasis on early mobilization, avoidance of overuse of opioid analgesics, early discharge with home care arrangements, use of a posthospitalization drainage tube with intraoperative surgical modifications using small incisions (4-5 cm), a narrow 20 mm retractor, minimal muscle injury, and use of a cell saver to minimize net blood loss. The demographics and perioperative results were compared with data from recent MIS-TLIF studies using Student t test for continuous and χ2/exact test for categorical variables.

RESULTS

Among the total 139 patients, 115 underwent a single-level procedure, 90% of whom were discharged on the first postoperative day (length of stay=1.13±0.47 d) with an average net estimated blood loss of 176.17±87.88 mL. There were 24 two-level procedures with an average length of stay of 1.57±0.84 days, average net estimated blood loss was 216.96±85.70 mL. The patients had statistically significant improvements in PROs at 3 and 12 months.

CONCLUSIONS

The results of this study identify that patients who underwent modified Open TLIF demonstrated favorable short-term outcomes, as compared with the tubular MIS-TLIF, by virtue of avoidance of blood transfusions, shorter hospital stays, and significantly less opioid usage while experiencing satisfactory PROs.

Does robot-assisted navigation influence pedicle screw selection and accuracy in minimally invasive spine surgery?

OBJECTIVE

The accuracy of percutaneous pedicle screw placement has increased with the advent of robotic and surgical navigation technologies. However, the effect of robotic intraoperative screw size and trajectory templating remains unclear. The purpose of this study was to compare pedicle screw sizes and accuracy of placement using robotic navigation (RN) versus skin-based intraoperative navigation (ION) alone in minimally invasive lumbar fusion procedures.

METHODS

A retrospective cohort study was conducted using a single-institution registry of spine procedures performed over a 4-year period. Patients who underwent 1- or 2-level primary or revision minimally invasive surgery (MIS)–transforaminal lumbar interbody fusion (TLIF) with pedicle screw placement, via either robotic assistance or surgical navigation alone, were included. Demographic, surgical, and radiographic data were collected. Pedicle screw type, quantity, length, diameter, and the presence of endplate breach or facet joint violation were assessed. Statistical analysis using the Student t-test and chi-square test was performed to evaluate the differences in pedicle screw sizes and the accuracy of placement between both groups.

RESULTS

Overall, 222 patients were included, of whom 92 underwent RN and 130 underwent ION MIS-TLIF. A total of 403 and 534 pedicle screws were placed with RN and ION, respectively. The mean screw diameters were 7.25 ± 0.81 mm and 6.72 ± 0.49 mm (p < 0.001) for the RN and ION groups, respectively. The mean screw length was 48.4 ± 4.48 mm in the RN group and 45.6 ± 3.46 mm in the ION group (p < 0.001). The rates of “ideal” pedicle screws in the RN and ION groups were comparable at 88.5% and 88.4% (p = 0.969), respectively. The overall screw placement was also similar. The RN cohort had 63.7% screws rated as good and 31.4% as acceptable, while 66.1% of ION-placed screws had good placement and 28.7% had acceptable placement (p = 0.661 and p = 0.595, respectively). There was a significant reduction in high-grade breaches in the RN group (0%, n = 0) compared with the ION group (1.2%, n = 17, p = 0.05).

CONCLUSIONS

The results of this study suggest that robotic assistance allows for placement of screws with greater screw diameter and length compared with surgical navigation alone, although with similarly high accuracy. These findings have implied that robotic platforms may allow for safe placement of the “optimal screw,” maximizing construct stability and, thus, the ability to obtain a successful fusion.

Robotics and Spine Surgery: Lessons From the Personal Computer and Industrial Revolutions

Over the past decade, several review articles have evaluated the techniques and outcomes of robotics vs traditional methods in spine surgery. Recently, robot-assisted pedicle screw placement has emerged, representing an important milestone in the evolution of spine surgery. In the present article, the authors aim to provide the historical context regarding the use and growth of spinal robotics through the lens of the Industrial Revolution and the personal computer revolution. While the former provides insight into the current implications of robotics in spine surgery, the latter predicts future steps in this arena.

Intraoperative Neuromonitoring During Lateral Lumbar Interbody Fusion

Objective

To review the evidence for the use of electromyography (EMG), motor-evoked potentials (MEPs), and somatosensory-evoked potentials (SSEPs) intraoperative neuromonitoring (IONM) strategies during lateral lumbar interbody fusion (LLIF), as well as discuss the limitations associated with each technique.

Methods

A comprehensive review of the literature and compilation of findings relating to clinical studies investigating the efficacy of EMG, MEP, SSEP, or combined IONM strategies during LLIF.

Results

The evidence for the use of EMG is mixed with some studies demonstrating the efficacy of EMG in preventing postoperative neurologic injuries and other studies demonstrating a high rate of postoperative neurologic deficits with EMG monitoring. Multimodal IONM strategies utilizing MEPs or saphenous SSEPs to monitor the lumbar plexus may be promising strategies based on results from a limited number of studies.

Conclusion

The use of traditional EMG during LLIF remains without consensus. There is a growing body of evidence utilizing multimodal IONM with MEPs or saphenous SSEPs demonstrating a possible decrease in postoperative neurologic injuries after LLIF. Future prospective studies, with clear definitions of neurologic injury, that evaluate different multimodal IONM strategies are needed to better assess the efficacy of IONM during LLIF.

Overview of Robotic Technology in Spine Surgery

As robotics in spine surgery has progressed over the past 2 decades, studies have shown mixed results on its clinical outcomes and economic impact. In this review, we highlight the evolution of robotic technology over the past 30 years, discussing early limitations and failures. We provide an overview of the history and evolution of currently available spinal robotic platforms and compare and contrast the available features of each. We conclude by summarizing the literature on robotic instrumentation accuracy in pedicle screw placement and clinical outcomes such as complication rates and briefly discuss the future of robotic spine surgery.

Facet Violation With Percutaneous Pedicle Screw Placement: Impact of 3D Navigation and Facet Orientation

Background: The gold standard for percutaneous pedicle screw placement is 2-dimensional (2D) fluoroscopy. Data are sparse on the accuracy of 3-dimensional (3D) navigation percutaneous screw placement in minimally invasive spine procedures. Objective: We sought to compare a single surgeon's percutaneous pedicle screw placement accuracy using 2D fluoroscopy versus 3D navigation, as well as to investigate the effect of facet orientation on facet violation when using 2D fluoroscopy. Methods: We conducted a retrospective radiographic study of consecutive cohort of patients who underwent percutaneous lumbar instrumentation using either 2D fluoroscopy or 3D navigation. All procedures were performed by a single surgeon at 2 academic institutions between 2011 and 2018. Radiographic measurement of screw accuracy was assessed using a postoperative computed tomographic scan. The primary outcome was facet violation, and secondary outcomes were endplate/tip breaches, the Gertzbein-Robbins classification for cortical breaches, and the Simplified Screw Accuracy grade. Statistical comparisons were made between screws placed using 2D fluoroscopy versus 3D navigation. Axial facet angles were also measured to correlate with facet violation rates. Results: In the 138 patients included, 376 screws were placed with fluoroscopy and 193 with navigation. Superior (unfused) level facet violation was higher with 2D fluoroscopy than with 3D navigation (9% vs 0.5%), which comprises the main cause for poor screw placement. Axial facet angles exceeding 45° at L4 and 60° at L5 were correlated with facet violations. Conclusion: This retrospective study found that 3D navigation is associated with lower facet violation rates in percutaneous lumbar pedicle screw placement when compared with 2D fluoroscopy. These findings suggest that 3D navigation may be of particular value when facet joints are coronally oriented.

Cervical Deformity: Evaluation, Classification, and Surgical Planning

Cervical deformity is a challenging condition to treat and requires complex decision-making. Apart from a thorough history and physical examination, a thoughtful and quantitative analysis of multiple imaging modalities is critical for understanding the nature and driver of the cervical deformity. A few classification schemes have emerged, and it is now clear that dynamic films are invaluable as they capture the extension reserve that patients can use to compensate for malalignment. These classification systems can help guide surgical planning, because the various subgroups have different properties that lend themselves to specific treatment paradigms. Here we review the clinical and radiographic evaluation, classification, and surgical planning for cervical deformity.

Trajectory of Improvement in Myelopathic Symptoms From 3 to 12 Months Following Surgery for Degenerative Cervical Myelopathy

BACKGROUND

Degenerative cervical myelopathy (DCM) is a progressive disease resulting from cervical cord compression. The modified Japanese Orthopaedic Association (mJOA) is commonly used to grade myelopathic symptoms, but its persistent postoperative improvement has not been previously explored.

OBJECTIVE

To utilize the Quality Outcomes Database (QOD) to evaluate the trajectory of outcomes in those operatively treated for DCM.

METHODS

This study is a retrospective analysis of prospectively collected data. The QOD was queried for patients undergoing elective surgery for DCM. Patients were divided into mild (≥14), moderate (9-13), or severe (<9) categories for their baseline severity of myelopathic symptoms (mJOA scores). A parsimonious multivariable logistic regression model was fitted with 2 points improvement on mJOA from 3- to 12-mo follow-up as the outcome of interest.

RESULTS

A total of 2156 patients who underwent elective surgery for DCM and had complete 3- and 12-mo follow-up were included in our analysis. Patients improved significantly from baseline to 3-mo on their mJOA scores, regardless of their baseline mJOA severity. After adjusting for the relevant preoperative characteristics, the baseline mJOA categories had significant impact on outcome of whether a patient keeps improving in mJOA score from 3 to 12 mo postsurgery. Patient with severe mJOA score at baseline had a higher likelihood of improvement in their myelopathic symptoms, compared to patients with mild mJOA score in.

CONCLUSION

Most patients achieve improvement on a shorter follow-up; however, patients with severe symptoms keep on improving until after a longer follow-up. Preoperative identification of such patients helps the clinician settling realistic expectations for each follow-up timepoint.

Does Neck Disability Index Correlate With 12-Month Satisfaction After Elective Surgery for Cervical Radiculopathy? Results From a National Spine Registry

BACKGROUND

Modern healthcare reforms focus on identifying and measuring the quality and value of care. Patient satisfaction is particularly important in the management of degenerative cervical radiculopathy (DCR) since it leads to significant neck pain and disability primarily affecting the patients' quality of life.

OBJECTIVE

To determine the association of baseline and 12-mo Neck Disability Index (NDI) with patient satisfaction after elective surgery for DCR.

METHODS

The Quality Outcomes Database cervical module was queried for patients who underwent elective surgery for DCR. A multivariable proportional odds regression model was fitted with 12-mo satisfaction as the outcome. The covariates for this model included patients' demographics, surgical characteristics, and baseline and 12-mo patient reported outcomes (PROs). Wald-statistics were calculated to determine the relative importance of each independent variable for 12-mo patient satisfaction.

RESULTS

The analysis included 2206 patients who underwent elective surgery for DCR. In multivariable analysis, after adjusting for baseline and surgery specific variables, the 12-mo NDI score showed the highest association with 12-mo satisfaction (Waldχ2-df = 99.17, 58.1% of total χ2). The level of satisfaction increases with decrease in 12-mo NDI score regardless of the baseline NDI score.

CONCLUSION

Our study identifies 12-mo NDI score as a very influential driver of 12-mo patient satisfaction after surgery for DCR. In addition, there are lesser contributions from other 12-mo PROs, baseline Numeric Rating Scale for arm pain and American Society of Anesthesiologists (ASA) grade. The baseline level of disability was found to be irrelevant to patients. They seemed to only value their current level of disability, compared to baseline, in rating satisfaction with surgical outcome.

Why are patients dissatisfied after spine surgery when improvements in disability and pain are clinically meaningful?

BACKGROUND CONTEXT

Studies have found that most patients are satisfied after spine surgery, with rates ranging from 53% to 90%. Patient satisfaction appears to be closely related to achieving clinical improvement in pain and disability after surgery. While the majority of the literature has focused on patients who report both satisfaction and clinical improvement in disability and pain, there remains an important subpopulation of patients who have clinically relevant improvement but report being dissatisfied with surgery.

PURPOSE

To examine why patients who achieve clinical improvement in disability or pain also report dissatisfaction at 1-year after spinal surgery.

STUDY DESIGN

Retrospective analysis of prospective data from a national spine registry, the Quality Outcomes Database.

PATIENT SAMPLE

There were 34,076 participants undergoing elective surgery for degenerative spine pathology who had clinical improvement in disability or pain.

OUTCOME MEASURES

Satisfaction with surgery was assessed with 1-item from the North American Spine Society lumbar spine outcome assessment. Participants with answer choices other than "treatment met my expectations" were classified as dissatisfied.

METHODS

Patients completed a baseline and 12-month postoperative assessment to evaluate disability, pain, and satisfaction. Clinical improvement was defined as patients who achieved a 30% or greater improvement in spine-related disability (Oswestry/Neck Disability Index) or extremity pain (11-point Numeric Rating Scale) from baseline to 12-month after surgery. A generalized linear mixed model was used to predict the odds of the patient being dissatisfied 1-year after surgery from demographic, clinical and surgical characteristics, postoperative complications and revision, and return to work and previous physical activity. Random effects were included to model the effect of both site and surgeon on dissatisfaction. Sensitivity analyses were conducted on samples who achieved 30% or greater improvement in (1) disability only, (2) axial (back/neck) pain only, (3) extremity (leg/arm)pain only, (4) both disability and axial pain, and (5) both disability and extremity pain. Results showed the same pattern of findings across all samples.

RESULTS

Twenty-eight percent of patients were classified as dissatisfied with their spine surgery and 72% classified as satisfied. For patients with clinical improvement in disability or extremity pain at 1-year, significant predictors of higher odds of dissatisfaction included baseline psychological distress, current smoking status, workers compensation claim, lower education, higher ASA grade, lumbar versus cervical procedure, and increased axial pain, major complication within 30 days, and revision surgery within 12-months. The most important contributors to dissatisfaction were return to work and return to previous physical activity, with the odds of dissatisfaction being over 2 times and 4 times higher for these variables. Site and surgeon explained 3.8% of the variance in dissatisfaction, with more of the variance attributed to site than to surgeon.

CONCLUSIONS

Several modifiable factors, including psychological distress, current smoking status, and failure to return to work and physical activity, helped explain why patients report being dissatisfied with surgery despite clinical improvement in disability or pain. The findings of this study have the potential to help providers identify at-risk patients, set realistic expectations during preoperative counseling, and implement postoperative management strategies. A multidisciplinary approach to rehabilitation that includes functional goal setting or restoration may help to improve patients psychological distress as well as return to work and previous physical activity after spine surgery.

Survival After Surgery for Renal Cell Carcinoma Metastatic to the Spine: Impact of Modern Systemic Therapies on Outcomes

BACKGROUND

Modern medical management of metastatic renal cell carcinoma (RCC) includes therapies targeting tyrosine kinases, growth pathways (mammalian target of rapamycin (mTOR)), and immune checkpoints.

OBJECTIVE

To test our hypothesis that patients with spinal metastases would benefit from postoperative systemic therapy despite presenting with disease that, in many cases, was resistant to prior systemic therapy.

METHODS

This is an Institutional Review Board-approved clinical retrospective cohort analysis. A sample of adult patients with RCC metastatic to the spine who underwent operative intervention between January 2010 and December 2017 at 2 large academic medical centers was used in this study.

RESULTS

We identified 78 patients with metastatic RCC in whom instrumented stabilization was performed in 79% and postoperative stereotactic radiosurgery was performed in 41% of patients. Of patients presenting with weakness or myelopathy, 93% noted postoperative improvement and 78% reported improvement in radicular and axial paraspinal pain severity. Increased overall survival (OS) (913 d (95% CI: 633-1975 d, n = 49) vs 222 d (95% CI: 143-1005 d, n = 29), P = .003) following surgery was noted in patients who received postoperative systemic therapy a median of 80 d (interquartile range 48-227 d) following the surgical intervention.

CONCLUSION

Postoperative outcomes and palliation of symptoms for metastatic RCC without targeted therapies in this cohort are similar to those reported in earlier series prior to the adoption of these systemic therapies. We observed a significantly longer OS among patients who received modern systemic therapies postoperatively. These findings have implications for the preoperative evaluation of patients with systemic disease who may have been deemed poor surgical candidates prior to the availability of these systemic therapies.

Drivers of Variability in 90-Day Cost for Elective Laminectomy and Fusion for Lumbar Degenerative Disease

BACKGROUND

Considerable variability exists in the cost of surgery following spine surgery for common degenerative spine diseases. This variation in the cost of surgery can affect the payment bundling during the postoperative 90 d.

OBJECTIVE

To determine the drivers of variability in total 90-d cost for laminectomy and fusion surgery.

METHODS

A total of 752 patients who underwent elective laminectomy and fusion for degenerative lumbar conditions and were enrolled into a prospective longitudinal registry were included in the study. Total cost during the 90-d global period was derived as sum of cost of surgery, cost associated with postdischarge utilization. Multivariable regression models were built for total 90-d cost.

RESULTS

The mean 90-d direct cost was $29 295 (range, $28 612-$29 973). Based on our regression tree analysis, the following variables were found to drive the 90-d cost: age, BMI, gender, diagnosis, postop imaging, number of operated levels, ASA grade, hypertension, arthritis, preop and postop opioid use, length of hospital stay, duration of surgery, 90-d readmission, outpatient physical/occupational therapy, inpatient rehab, postop healthcare visits, postop nonopioid pain medication use nonsteroidal antiinflammatory drug (NSAIDs), and muscle relaxant use. The R2 for tree model was 0.64.

CONCLUSION

Utilizing prospectively collected data, we demonstrate that considerable variation exists in total 90-d cost, nearly 70% of which can be explained by those factors included in our modeling. Risk-adjusted payment schemes can be crafted utilizing the significant drivers presented here. Focused interventions to target some of the modifiable factors have potential to reduce cost and increase the value of care.

Impact of occupational characteristics on return to work for employed patients after elective lumbar spine surgery

BACKGROUND CONTEXT

Low back pain has an immense impact on the US economy. A significant number of patients undergo surgical management in order to regain meaningful functionality in daily life and in the workplace. Return to work (RTW) is a key metric in surgical outcomes, as it has profound implications for both individual patients and the economy at large.

PURPOSE

In this study, we investigated the factors associated with RTW in patients who achieved otherwise favorable outcomes after lumbar spine surgery.

STUDY DESIGN/SETTING

This study retrospectively analyzes prospectively collected data from the lumbar module of national spine registry, the Quality Outcomes Database (QOD).

PATIENT SAMPLE

The lumbar module of QOD includes patients undergoing lumbar surgery for primary stenosis, disc herniation, spondylolisthesis (Grade I) and symptomatic mechanical disc collapse or revision surgery for recurrent same-level disc herniation, pseudarthrosis, and adjacent segment disease. Exclusion criteria included age under 18 years and diagnoses of infection, tumor, or trauma as the cause of lumbar-related pain.

OUTCOME MEASURES

The outcome of interest for this study was the return to work 12-month after surgery.

METHODS

The lumbar module of QOD was queried for patients who were employed at the time of surgery. Good outcomes were defined as patients who had no adverse events (readmissions/complications), had achieved 30% improvement in Oswestry disability index (ODI) and were satisfied (NASS satisfaction) at 3-month post-surgery. Distinct multivariable logistic regression models were fitted with 12-month RTW as outcome for a. overall population and b. the patients with good outcomes. The variables included in the models were age, gender, race, insurance type, education level, occupation type, currently working/on-leave status, workers' compensation, ambulatory status, smoking status, anxiety, depression, symptom duration, number of spinal levels, diabetes, motor deficit, and preoperative back-pain, leg-pain and ODI score.

RESULTS

Of the total 12,435 patients, 10,604 (85.3%) had successful RTW at 1-year postsurgery. Among patients who achieved good surgical outcomes, 605 (7%) failed to RTW. For both the overall and subgroup analysis, older patients had lower odds of RTW. Females had lower odds of RTW compared with males and patients with higher back pain and baseline ODI had lower odds of RTW. Patients with longer duration of symptoms, more physically demanding occupations, worker's compensation claim and those who had short-term disability leave at the time of surgery had lower odds of RTW independent of their good surgical outcomes.

CONCLUSIONS

This study identifies certain risk factors for failure to RTW independent of surgical outcomes. Most of these risk factors are occupational; hence, involving the patient's employer in treatment process and setting realistic expectations may help improve the patients' work-related functionality.

A predictive model and nomogram for predicting return to work at 3 months after cervical spine surgery: an analysis from the Quality Outcomes Database

OBJECTIVEBack pain and neck pain are two of the most common causes of work loss due to disability, which poses an economic burden on society. Due to recent changes in healthcare policies, patient-centered outcomes including return to work have been increasingly prioritized by physicians and hospitals to optimize healthcare delivery. In this study, the authors used a national spine registry to identify clinical factors associated with return to work at 3 months among patients undergoing a cervical spine surgery.METHODSThe authors queried the Quality Outcomes Database registry for information collected from April 2013 through March 2017 for preoperatively employed patients undergoing cervical spine surgery for degenerative spine disease. Covariates included demographic, clinical, and operative variables, and baseline patient-reported outcomes. Multiple imputations were used for missing values and multivariable logistic regression analysis was used to identify factors associated with higher odds of returning to work. Bootstrap resampling (200 iterations) was used to assess the validity of the model. A nomogram was constructed using the results of the multivariable model.RESULTSA total of 4689 patients were analyzed, of whom 82.2% (n = 3854) returned to work at 3 months postoperatively. Among previously employed and working patients, 89.3% (n = 3443) returned to work compared to 52.3% (n = 411) among those who were employed but not working (e.g., were on a leave) at the time of surgery (p < 0.001). On multivariable logistic regression the authors found that patients who were less likely to return to work were older (age > 56-65 years: OR 0.69, 95% CI 0.57-0.85, p < 0.001; age > 65 years: OR 0.65, 95% CI 0.43-0.97, p = 0.02); were employed but not working (OR 0.24, 95% CI 0.20-0.29, p < 0.001); were employed part time (OR 0.56, 95% CI 0.42-0.76, p < 0.001); had a heavy-intensity (OR 0.42, 95% CI 0.32-0.54, p < 0.001) or medium-intensity (OR 0.59, 95% CI 0.46-0.76, p < 0.001) occupation compared to a sedentary occupation type; had workers' compensation (OR 0.38, 95% CI 0.28-0.53, p < 0.001); had a higher Neck Disability Index score at baseline (OR 0.60, 95% CI 0.51-0.70, p = 0.017); were more likely to present with myelopathy (OR 0.52, 95% CI 0.42-0.63, p < 0.001); and had more levels fused (3-5 levels: OR 0.46, 95% CI 0.35-0.61, p < 0.001). Using the multivariable analysis, the authors then constructed a nomogram to predict return to work, which was found to have an area under the curve of 0.812 and good validity.CONCLUSIONSReturn to work is a crucial outcome that is being increasingly prioritized for employed patients undergoing spine surgery. The results from this study could help surgeons identify at-risk patients so that preoperative expectations could be discussed more comprehensively.

Drivers of Variability in 90-Day Cost for Elective Anterior Cervical Discectomy and Fusion for Cervical Degenerative Disease

BACKGROUND

Value-based episode of care reimbursement models is being investigated to curb unsustainable health care costs. Any variation in the cost of index spine surgery can affect the payment bundling during the 90-d global period.

OBJECTIVE

To determine the drivers of variability in cost for patients undergoing elective anterior cervical discectomy and fusion (ACDF) for degenerative cervical spine disease.

METHODS

Four hundred forty-five patients undergoing elective ACDF for cervical spine degenerative diagnoses were included in the study. The direct 90-d cost was derived as sum of cost of surgery, cost associated with postdischarge utilization. Multiple variable linear regression models were built for total 90-d cost.

RESULTS

The mean 90-d direct cost was $17685 ± $5731. In a multiple variable linear regression model, the length of surgery, number of levels involved, length of hospital stay, preoperative history of anticoagulation medication, health-care resource utilization including number of imaging, any complications and readmission encounter were the significant contributor to the 90-d cost. The model performance as measured by R2 was 0.616.

CONCLUSION

There was considerable variation in total 90-d cost for elective ACDF surgery. Our model can explain about 62% of these variations in 90-d cost. The episode of care reimbursement models needs to take into account these variations and be inclusive of the factors that drive the variation in cost to develop a sustainable payment model. The generalized applicability should take in to account the differences in patient population, surgeons' and institution-specific differences.

Predictors of patient satisfaction following 1- or 2-level anterior cervical discectomy and fusion: insights from the Quality Outcomes Database

OBJECTIVE

Patient satisfaction with treatment outcome is gaining an increasingly important role in assessing the value of surgical spine care delivery. Nationwide data evaluating the predictors of patient satisfaction in elective cervical spine surgery are lacking. The authors sought to decipher the impacts of the patient, surgical practice, and surgeon on satisfaction with outcome following anterior cervical discectomy and fusion (ACDF).

METHODS

The authors queried the Quality Outcomes Database for patients undergoing 1- to 2-level ACDF for degenerative spine disease since 2013. Patient satisfaction with the surgical outcome as measured by the North American Spine Society (NASS) scale comprised the primary outcome. A multivariable proportional odds logistic regression model was constructed with adjustments for baseline patient characteristics and surgical practice and surgeon characteristics as fixed effects.

RESULTS

A total of 4148 patients (median age 54 years, 48% males) with complete 12-month NASS satisfaction data were analyzed. Sixty-seven percent of patients answered that "surgery met their expectations" (n = 2803), while 20% reported that they "did not improve as much as they had hoped but they would undergo the same operation for the same results" (n = 836). After adjusting for a multitude of patient-specific as well as hospital- and surgeon-related factors, the authors found baseline Neck Disability Index (NDI) score, US geographic region of hospital, patient race, insurance status, symptom duration, and Workers' compensation status to be the most important predictors of patient satisfaction. The discriminative ability of the model was satisfactory (c-index 0.66, overfitting-corrected estimate 0.64).

CONCLUSIONS

The authors' results found baseline NDI score, patient race, insurance status, symptom duration, and Workers' compensation status as well as the geographic region of the hospital to be the most important predictors of long-term patient satisfaction after a 1- to 2-level ACDF. The findings of the present analysis further reinforce the role of preoperative discussion with patients on setting treatment goals and realistic expectations.

Effect of Depression on Patient-Reported Outcomes Following Cervical Epidural Steroid Injection for Degenerative Spine Disease

Objective

To assess the effect depression has on outcomes after cervical epidural steroid injections (CESIs).

Design

Retrospective review of a prospectively collected database.

Setting

Single institution tertiary care center.

Subjects

Fifty-seven patients with cervical spondylosis and cervical radicular pain who were deemed appropriate surgical candidates but elected to undergo CESI first were included.

Methods

Twenty-one of 57 (37%) patients with depression (defined as Zung Depression Scale >33) were included. Patient-reported outcomes including Neck Disability Index (NDI), numeric rating scale (NRS) for arm pain (AP), NRS for neck pain (NP), and EuroQol-5D (EQ-5D) were collected at baseline and three-month follow-up. Minimal clinically important differences were then calculated to provide dichotomous outcome measures of success.

Results

Overall, 24 and 28 patients achieved at least 50% improvement in AP and NP, respectively. In terms of disability, 25/57 (43.9%) patients achieved >13.2-point improvement on the NDI overall. In patients with depression, 4/21 (19.0%) and 5/21 (23.8%) achieved at least 50% improvement on the NRS for AP and NP, respectively, compared with 20/36 (55.5%) and 23/36 (63.8%) in patients without depression. This difference was statistically significant for both pain measures (P < 0.002 AP, P < 0.006 NP). Statistically fewer patients, 5/21 (24%), with depression achieved ≥13.2-point improvement on the NDI compared with 20/36 (55%) nondepressed patients (P < 0.01). There was no difference in outcomes between groups on the EQ-5D.

Conclusions

Patients with cervical spondylosis and comorbid depression who undergo CESI are less likely to achieve successful outcomes in both pain and function compared with nondepressed patients at three months.

The Legacy of a Neurosurgeon: A U.S.-Based Obituary Analysis

BACKGROUND

Textual analysis of obituaries provides insight into the shared values of a profession or community. Neurosurgeon obituaries are frequently published in both the medical literature and the lay press, but the content of these works has never been analyzed.

METHODS

Using obituary pieces from Neurosurgery, Journal of Neurosurgery, and the New York Times, frequent terms were quantified through preliminary text analysis to derive the relative importance of concepts such as innovation, research, training and family. The sentiment of these obituaries was qualitatively reviewed to approximate perceptions of neurosurgical legacy within the profession and the general public.

RESULTS

Thirty relevant obituaries with full text available were identified in the Journal of Neurosurgery, 14 were identified in Neurosurgery, and 23 were identified in the New York Times. Both neurosurgical journals and lay press articles relied on linear narratives, with greater emphasis on professional leadership and residency training in neurosurgical journals and proportionally greater mention of family in the lay press.

CONCLUSIONS

Our preliminary text analysis of neurosurgeon obituaries suggest what values are shared among the professional community and general public regarding the legacy of a neurosurgeon.

Comparing different chronic preoperative opioid use definitions on outcomes after spine surgery

BACKGROUND CONTEXT

No consensus exists for defining chronic preoperative opioid use. Most spine studies rely solely on opioid duration to stratify patients into preoperative risk categories.

PURPOSE

The purpose of this study is to compare established opioid definitions that contain both duration and dosage to opioid models that rely solely on duration, including the CDC Guideline for Prescribing Opioids for Chronic Pain, in patients undergoing spine surgery.

STUDY DESIGN

This was a retrospective cohort study that used opioid data from the Tennessee Controlled Substance Monitoring Database and prospective clinical data from a single-center academic spine registry.

PATIENT SAMPLE

The study cohort consisted of 2,373 patients who underwent elective spine surgery for degenerative conditions between January 2011 and February 2017 and who completed a follow-up assessment at 12 months after surgery.

OUTCOME MEASURES

Postoperative opioid use and patient-reported satisfaction (NASS Satisfaction Scale), disability (Oswestry/Neck Disability Index), and pain (Numeric Rating Scale) at 12 month follow-up.

METHODS

Six different chronic preoperative opioid use variables were created based on the number of times a prescription was filled and/or daily morphine milligram equivalent for the one year before surgery. These variables defined chronic opioid use as 1) most days for > 3 months (CDC), 2) continuous use for ≥ 6 months (Schoenfeld), 3) >4,500 mg for at least 9 months (Svendsen wide), 4) >9,000 mg for 12 months (Svendsen intermediary), 5) >18,000 mg for 12 months (Svendsen strict), 6) low-dose chronic (1-36 mg for >91 days), medium-dose chronic (36-120 mg for >91 days), and high-dose chronic (>120 mg for >91 days) (Edlund). Multivariable regression models yielding C-index and R² values were used to compare chronic preoperative opioid use definitions by postoperative outcomes, adjusting for type of surgery.

RESULTS

Chronic preoperative opioid use was reported in 470 to 725 (19.8% to 30.6%) patients, depending on definition. The Edlund definition, accounting for duration and dosage, had the highest predictive ability for postoperative opioid use (77.5%), followed by Schoenfeld (75.7%), CDC (72.6%), and Svendsen (59.9% to 72.5%) definitions. A combined Edlund and Schoenfeld duration and dosage definition in post-hoc analysis, that included 3 and 6 month duration cut-offs, performed the best overall with a C-index of 78.4%. Both Edlund and Schoenfeld definitions explained similar amounts of variance in satisfaction, disability, and pain (4.2% to 8.5%). Svendsen and CDC definitions demonstrated poorer performance for patient-reported outcomes (1.4% to 7.2%).

CONCLUSIONS

The Edlund definition is recommended for identifying patients at highest risk for postoperative opioid use. When opioid dosage is unavailable, the Schoenfeld definition is a reasonable choice with similar predictive ability. For patient-reported outcomes, either the Edlund or Schoenfeld definition is recommended. Future work should consider combing dosage and duration, with 3 and 6 month cutoffs, into chronic opioid use definitions.

Emergency Department Visits After Elective Spine Surgery

BACKGROUND

Emergency department (ED) overuse is a costly and often neglected source of postdischarge resource utilization after spine surgery. Failing to investigate drivers of ED visits represents a missed opportunity to improve the value of care in spine patients.

OBJECTIVE

To identify the prevalence, drivers, and timing of ED visits following elective spine surgery.

METHODS

Patients undergoing elective spine surgery for degenerative disease at a major medical center were enrolled in a prospective longitudinal registry. Patient and surgery characteristics, and patient-reported outcomes were recorded at baseline and 3 mo after surgery, along with self-reported 90-d ED visits. A multivariable regression model was used to identify independent factors associated with 90-d ED visits. For a sample of patients presenting to our institution's ED, charts were reviewed to identify the reason and time to ED postdischarge.

RESULTS

Of 2762 patients, we found a 90-d ED visit rate of 9.4%. One-third of patients presented to our institution's ED and of these, 70% presented due to pain or medical concerns at 9 and 7 d postdischarge, respectively, with 60% presenting outside normal clinic hours. Independent risk factors for 90-d ED visits included younger age, preoperative opioid use, chronic obstructive pulmonary disorder, and more vertebral levels involved.

CONCLUSION

Nearly 10% of elective spine patients had 90-d ED visits not requiring readmission. Pain and medical concerns accounted for 70% of visits at our center, occurring within 10 d of discharge. This study provides the clinical details and a timeline necessary to guide individualized interventions to prevent unnecessary, costly ED visits after spine surgery.